1. Field of the Invention
The invention relates generally to cage and rack systems for housing animals, and more particularly to a ventilated cage and rack system for housing animals.
2. Description of Related Art
It is well known in the art to house laboratory animals, such as mice and rats, in cages. It is also well known in the art to house the cages on racks. These cages are typically ventilated and, when placed in a rack, environmentally controlled (e.g., air-flow and air-exchange rate) by a fan system of the rack. In general, in such ventilated cage and rack systems, the rack fan system provides air under pressure to each of the cages within the rack, and exhausts air from the cages and the rack.
One such ventilated cage and rack system is disclosed in U.S. Pat. No. 6,158,387, assigned to Lab Products, Inc., in which a rack includes an air exhaust plenum and a canopy. The
Thus, while there have been shown and described and pointed out novel features of the present invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. canopy is capable of supporting a cage within the rack above the canopy, and also positioning another cage below the canopy so as to permit air to be drawn into the air exhaust plenum from the interior of the second cage through the top of the second cage and to also permit ambient air to be drawn across the top of the second cage into the air exhaust plenum. Cages for such systems may be referred to as cage level barrier cages because they provide for a barrier between the interior and exterior of the cage such that contaminants from the interior of the cage do not readily leave the cage, and likewise, contaminants from the exterior of the cage do not readily enter the interior of the cage.
This related ventilated cage and rack system was satisfactory. However, due to the manner in which the cage is positioned within the rack, only a single width of container may be accommodated by the rack.
In some situations, however, personnel may benefit from the use of cages having different widths. This situation may arise when a study is performed using animals of different species or sizes. A larger animal, or different species of animal, may require a larger cage size than another. Additionally, for the purposes of a study, it may be desirable to house a larger number of animals in one cage than in another, consequently requiring different size cages. Furthermore, in some circumstances, a single cage size may be used, with a larger than needed cage being used for containing animals. This strategy, however, typically leads to a waste of valuable space. Additionally, two different racks may be used, each rack accommodating a different size cage, but again, this strategy also tends to lead to the wasting of valuable space. As such, a need exists for an improved ventilated cage and rack system.